i have just been wondering about this lately. i tried searching but couldnt find anything recent or related to the a4 2.0t.

i just wanted to know if there are any real side effects from adding a Forge dv spacer or bov/dv splitter. i know that audi uses a closed loop system and its just a noise maker, but does it actually hurt the performance of the car? why does audi use a closed loop system?
can anyone explain it in techinal detail? i know that when the throttle closes, the turbo is still moving air and that air, "boost", has to go somewhere. so a bov just vents it into the atmosphere and a dv reroutes it back into the air intake system. but what are the benefits of recirculation? besides avoiding a CEL :-P

 

oh man, you know what they call you at our forum? lol jk we dont, we just close thread like this.

link please read because you want to know more in techincal details. Read until your heart desire.

BOV FAQ: The REAL dirt on BOVs. Ups AND downs. Lets dispell some myths. - NASIOC

Please enjoy, if you find this helpful, please leave me a message, thanks.

*edit* There is no discussion about this subject what so ever unless you have a bouche 20xt-r making 350+whp with 22psi *edit*

 

Lol you talking about audizine?
Thanks for the info, ill check it out.

 

BOV = waste of money

the Forge diverter valve is nice because its piston operated and not diaphram.... The new 2.0 chain drives uses a piston setup now.

BOV....? if it was more efficient to vent to atmosphere than to re-circ was does every manufacturer use a re-circ system....?

 

honestly I don't believe it has to do so much with efficiency as it has to do with marketing. car manufacturers probably use re-circ valves instead of BOV's to draw a bigger crowd with bigger wallets. not everyone likes the "psssh" sound. but when the car doesn't make any sound at all, more people are gonna like it because its less of a nuisance and less of an attention grabber. not every person that wants a turbo audi is a younger kid.. plus, most of the younger age groups don't have the money to buy one of these cars until the cars are 10 years old and theres been research done and parts made to fit different styles and choices. i'm sure there is a bit of an efficiency benefit, but honestly they both work fine. the BOV just needs a little tweaking to make it work on a stock/almost stock car. if re-circs were really that much more efficient though, why wouldn't builders use those instead of BOV's on top end dragsters and le mans cars and the like?